This invention relates to a system for enhancing the hearing of persons who are hard of hearing and use conventional hearing aids.
Hearing aids as conventionally used are equipped with a T switch which allows inductive coupling of the hearing aid with the ear-piece of a telephone handset. Similar inductive coupling can also be provided by an induction loop to which audio signals are fed via a microphone and amplifier. Inductive loops of this nature are conventionally provided in public places such as churches and halls, the loop being positioned around the public space and fed from a microphone used by a spearer. It is of the essence of loops of this nature that the same signals will be heard by persons using hearing aids at any position within the loop.
It is also known to provide more localised induction loops to enable staff dealing with the public, for example, at Post Offices and railway ticket offices, to converse with a customer. Such installations, however, suffer from the disadvantages that they are relatively complex and expensive to install, and they have a low level of privacy which may be of concern to the hard of hearing in locations such as banks. They also have the drawback that the hearing enhancement can only be provided at fixed locations, and they are therefore unsuitable for use in situations such as large showrooms or hospital consulting suites.
An object of the present invention is to provide a system for aiding communication with the hard of hearing which avoids or reduces the foregoing disadvantages.
The present invention accordingly provides a hearing enhancement system for use by a first person in communicating with a second person, one or the persons having impaired hearing and using a hearing aid equipped with a selectively actuable inductive coupling (or T switch); the system comprising a microphone, an amplifier, a power supply, and an inductive loop; at least the amplifier power supply and inductive loop being connected together as a unitary article adapted to be readily worn on and removed from the body of one of the persons, and in which the inductive loop is a flexible elongate member which, in use, is worn around the body of said person.
The flexible elongate member may be a permanently closed loop of a size to be worn draped from one shoulder across the user""s body. Alternatively, the flexible elongate member may be provided with a releasable closure to enable it to be worn around the waist in the manner of a waist belt.
In one form, the microphone, the amplifier and the power supply are secured directly to the flexible elongate member. Where the flexible elongate member is worn draped across one shoulder, the amplifier and/or the power supply may be positioned at the lowest point of the loop adjacent to the user""s waist, with the microphone positioned on the loop to be adjacent to the user""s chest or shoulder. Alternatively, a separate microphone may be used.
The power supply may conveniently comprise a re-chargeable battery pack of the type used in portable telephones, or photovoltaic cells, or a combination of these.
The inductive loop may be formed by a length of flexible flat ribbon cable of a type well known per se. The ends of the length of ribbon cable may be joined together by a connector assembly with the conductors of the cable offset by one pitch, thereby forming a multi-turn coil. A 10 conductor or 20 conductor ribbon cable will be suitable for many applications.
The inductive loop or each inductive loop has between 5 and 50 turns. The inductive loop may alternatively be in the form of insulated single-conductor wire wound into a loop which may, for example, be enclosed in a soft plastic sleeve.
Preferably, the inductive loop is provided with switching means by which the user may select a smaller or a larger number of turns (for example, 10 or 20 turns) to provide a selection of very close range (c. 1 m) or close range (c. 2-3 m) communication. Alternatively, there may be a single loop driven by an amplifier the gain of which may be switched between low and high by the user.
One embodiment of the present invention will now be described, by way of example only, with reference to the drawings, in which: